german cardinal joseph ratzinger was 78 years old when he became pope in april 2005 following the death of pope john paul ii. he was the oldest person to become pontiff in 275 years. benedict xvi was a conservative pope, he strongly opposed to birth control, but he embraced new forms of communication and joined twitter last year. pope benedict faced a string of challenges during his term from sexual abuse scandals involving the members of the clergy to an investigation into money laundering in vatican city. a court convicted his former butler last year of stealing and leaking classified documents that pointed to corruption in the vatican. the pope pardoned him over christmas. it's rare for a pope to resign. pope benedict is the first to quit in nearly 600 years. senior members of the catholic church will now start planning their conclave, the meeting they hold to choose a successor. >>> police in the united states are investigating yet another case of gun violence. pop ben fikt benedict xvi will be one of the most religious thinkers of the age. >> the president says he has warm memories